Care guide for discus fish (Symphysodon discus)
In many forums on the internet you will find that they recommend strict practices such as 100% water changes every day, but in reality, only a small percentage of people are able to follow those rules, and the rest of the world uses more less strict methods of maintenance..
We have spent many years personally keeping discus fish at home, and helping friends succeed with them.
Based on our experiences, this care guide offers practical and helpful advice for beginners starting their first discus tank.
Discus Fish – The King of the Aquarium
There are at least 3 described species and there is some debate related to the validity of the scientific names that have been assigned. Wild-caught discus fish can be difficult to keep because of their special water chemistry and nutritional needs.
However, most discus fish sold today are captive bred and are much easier to care for. That said, they are not for beginners for a variety of reasons. Through selective breeding, numerous color varieties are available and more continue to be developed.
Discus fish natural habitat
Discus fish are found in floodplain lakes and in flooded forests of the lower Amazon River and some of its tributaries, including the Negro River.
These areas experience extreme changes in water level due to seasonal flooding. Discus tend to congregate near fallen trees, along the shoreline. They prefer calm waters and are rarely found in areas where there is strong current or wave action.
Aquarium requirements for discus fish
Also, by heating the tank, their metabolism goes up, you have to feed them more, and then more waste is created. (This is why people recommend doing all those frequent water changes.)
The movement of the water should be gentle, and the decoration should include large broad-leaved plants and wooden logs that are arranged vertically to simulate branches and fallen trees. Make sure you find plants that can tolerate high temperatures like anubias or java fern.
Some floating plants can also be added to provide areas of shade and cover. Substrate should be fine to medium grade sand or gravel with a smooth surface like a disk to search for food on the bottom.
We also recommend adding air stones since having a higher temperature in the water decreases the amount of oxygen in the water. In the summer, when the weather gets hotter than normal, an air stone can help decrease the risk of low oxygen levels.
What size tank is needed for discus fish?
Many hobbyists ask, “ Can I have just one discus fish? Technically, the answer is yes. For example, dogs are technically pack animals, but many people have only one and then leave them alone at home all day. It’s not ideal, but it’s doable. The same applies with the disk.
However, Discus are naturally schooling fish and are much happier when surrounded by a large group of their own kind. Also, as a type of cichlid, they can start to bully others if you don’t have a decent sized group.
To mitigate this territorial aggression, buy 10 or 12 juveniles at a time for your 280 liter tank. Make sure they are roughly the same size so that no discus is left behind when it comes to food.
You should end up with a nice and relatively peaceful group of six adult discus with mostly females and maybe a couple of males.
Discus fish water needs
A minimum of 10% to 25% weekly water changes are recommended using a siphon vacuum gravel cleaner like this one. And don’t forget to treat your tap water with a good water conditioner before refilling your aquarium.
What is the ideal temperature for records?
The reason is that the discus farms they come from tend to keep their waters at these temperatures, and when we try to force them to cool down, it becomes a source of problems.
When the heat stays high, the discs become more active, their metabolism works well, they grow faster, and they show brighter colors. So if you want to successfully care for your discus, be willing to make this necessary change, which may differ from your normal fish keeping habits.
You will most likely need to use an aquarium heater like the Eheim Jager to maintain the proper water temperature. While captive-bred discus can be kept in chlorine-free tap water, reverse osmosis or deionized water will provide the best conditions.
Other water levels to consider
In our experience, captive bred discus fish do well when the pH levels are between 6.8 and 7.6. The same applies with the hardness of the water; discs are usually fine with soft to medium hardness, between 1° and 4° dKH (18 to 70 ppm).
We haven’t kept German Breed Discus yet, but they are known to tolerate higher pH and harder water.
If you want to focus on discus breeding and rearing, you will need a much lower water pH and hardness, but if you are simply keeping them for pleasure, these two water parameters are not that important.
Do discs really need daily water changes?
Other considerations include the size of the tank, the number of Discus you have, the amount of food you feed them, and the amount of biological filtration (such as beneficial bacteria and live plants) you have.
As a general rule of thumb, we recommend keeping the nitrate level below 40 ppm for planted tanks and below 20 ppm for non-planted tanks.
To find out how often you need to do water changes in your aquarium, get an aquarium water test kit like this one and keep an eye on the levels.
What fish are good companions for discus fish?
Most experienced hobbyists do not mix their discus with too many other species. However, tankmates must meet two criteria: they must be able to live in high temperatures, and they cannot compete with discus fish for food.
In general, discus feed slowly, so if you put them with fast fish like barbels or tetras, the discus will tend to lose that race. Even other warm water fish like angelfish can be too fast for them.
Instead, consider starting with a discus-only tank where discus are the main fish. Once they feed well, you can gradually add cardinal tetras, neons, emperors or maybe a Pleco or pool cleaner, clown loaches or dwarf cichlids. All of these fish tolerate the high temperatures and low pH/hardness that discus requires.
However, avoid having too many tankmates, or else the discus may have nutrition problems.
What is the best food for discus fish?
Most people feed them food that is too big, not realizing that discus mouths are quite small. So, if you see them eating, then spitting out the food, and finally eating it again, you may have a problem with the size of your meal.
They can be fed Tropical Flakes, Color Flakes, Spirulina Flakes, Tropical Granules, Algae Wheels, and Shrimp Pellets.
Frozen and live foods should also be provided as treats or to help induce spawning. Frozen bloodworms are great because their slim shape is perfect for slurping, but pucks can get addicted to them pretty easily.
Other suggestions include frozen or live shrimp, live or freeze-dried black worms, and live microgerms.
For best results, rotate their diet daily and feed only what they can consume in 2-3 minutes, once or twice a day.
Make sure you feed them a wide variety of small foods to cover all the nutrients they need. For example, some of the best-selling discus fish foods:
Discus Fish Reproduction
After hatching, the young feed on the heavy body mucus secreted by the parents for a few days until they begin to swim freely. Parents move young from one place to another several times a day.
Why are discus fish so expensive?
It is a very time and labor intensive job, especially as discus take longer to reach their adult size compared to other cheaper fish like guppies.
You can buy discus fish at local hatcheries, fish stores, or even online, but if you’ve never owned discus before, our best advice is to stay away from extreme prices.
In other words, don’t buy the cheapest ones that may have quality issues, and don’t buy the $300 adults that may die from your lack of experience. Just remember to buy a group of them that are all the same size to minimize bullying problems.
How to keep discus fish happy?
Keep children from hitting the glass and limit the amount of traffic near your tank. Also, don’t put your aquarium right next to the TV with lots of loud noises and flashing lights.
Anything you can do to help these shy creatures feel safe will go a long way toward improving their health and quality of life.
Lastly, don’t forget to reduce your own stress! Many beginning discus owners spend too much time worrying about accidentally damaging their discus, instead of relaxing and appreciating its majestic beauty.
With these simple guidelines, you are well on your way to having a successful and enjoyable discus tank for years to come.